Residential booster pump systems are known that provide the water supply system in a residence with additional/supplemental pressure to the incoming “city pressure” provided from a public water supply system. Typically, the controls for such booster pumps utilize an on/off pressure type switch wherein the booster pump starts when the water pressure in the home drops to a preselected start pressure and the booster pump runs until a preselected stop pressure is reached, with both the start and stop pressures being greater than the “city pressure” at the inlet side of the booster pump. Typically, these preset pressures are 20-40 psi, 30-50 psi and 40-60 psi, with the lower pressure being the start pressure and the upper pressure being the stop pressure. These systems require a relatively large diaphragm pressure tank in order to prevent short cycling of the booster pump.
It is also known to control a residential booster pump by starting the booster pump when the home pressure drops to a preselected start pressure and stopping the pump when the flow rate through the booster pump reaches a preselected “low flow rate”. These systems are also capable of starting at a preselected flow rate if that is encountered before the preselected start pressure. One advantage of such a control over the on/off pressure type switch is that a large diaphragm tank is not required. However, a smaller diaphragm tank (for example a two-gallon diaphragm tank) should be installed with such systems to account for small leaks and thermal expansion from any water heaters in the system.